Overview
IEC TS 60904-13:2018 - Photovoltaic devices, Part 13: Electroluminescence of photovoltaic modules specifies standardized methods for capturing, processing and interpreting electroluminescence (EL) images of photovoltaic (PV) modules. The technical specification covers equipment, imaging procedures, image-correction and quantitative metrics, and offers guidance for qualitative interpretation of EL features. It applies to PV modules measured with a power supply that places the cells in forward bias.
Keywords: IEC TS 60904-13:2018, electroluminescence, EL imaging, PV modules, photovoltaic testing standards.
Key Topics and Requirements
- Imaging apparatus: requirements for EL cameras/detectors, dark-room or controlled imaging environment, power-supply setup, computer interfaces and imaging software.
- Imaging procedure: camera positioning, exposure and focus settings, frame subtraction, sharpness determination and classification.
- Image correction: normative procedures for removing dark current and stray light, and correcting lens effects such as vignetting.
- Signal quality: methods to assess image signal-to-noise ratio (SNR) and minimum quality criteria for reliable interpretation.
- Image analysis & metrics:
- Histogram-based analyses (variance, skewness, kurtosis).
- Pixel- or area-weighted EL relative to an ideal module.
- Quantification frameworks for features such as cell cracks and inactive areas.
- Physical interpretation: linking EL observables to PV electrical properties (series resistance, shunt resistance, minority-carrier lifetime/diffusion length) and common failure modes.
- Annexed methods: focus assessment (Tenengrad, Sobel), quantitative crack analysis, and qualitative interpretation tables for crystalline silicon and thin-film modules.
- Reporting: standardized content and labeling (cell coordinates, orientation) for reproducible EL test reports.
Practical Applications
- Quality control and factory acceptance testing for PV module manufacturers.
- Field and laboratory diagnostics during commissioning, maintenance and warranty inspections.
- R&D and failure analysis to correlate EL features with module performance degradation.
- Asset owners and O&M providers using EL imaging for nondestructive testing, crack mapping, hotspot detection and degradation trend analysis.
Keywords: PV inspection, nondestructive testing, module diagnostics, EL image processing, solar module inspection.
Who Should Use This Standard
- PV module manufacturers and quality engineers
- Independent test laboratories and certification bodies
- O&M providers and field service technicians
- Researchers and developers in photovoltaic materials and reliability
- Warranty assessors and asset managers
Related Standards
- Other parts of the IEC 60904 series (Photovoltaic devices) cover complementary PV test methods and may be referenced for broader photovoltaic testing and performance evaluation.